1. Technical Field
The present invention generally relates to the treatment of tissue via energy delivery. More particularly, certain embodiments of the present invention relate to thermal ablation of lung tissue with energy delivered via a piercing needle.
2. Description of the Related Art
Lung cancer has a high incidence of morbidity and mortality in patients. Early stages of lung cancer can take the form of pulmonary nodules (in particular those under between 0.5 mm and 30 mm in size) and may require careful evaluation by a medical professional, especially in patients that have risk factors such as tobacco use or a family history of cancer.
Lung nodules, lesions, tumors, and other cancerous or pre-cancerous regions of tissue in the lung, may be difficult to treat with invasive surgical techniques, with attendant complications such as excessive bleeding, infection risk, air leaks, pneumothorax, and other such issues. In particular, regions deep in the lung may be difficult to access using conventional methods, further increasing the difficulty of treatment.
Electrical ablation, in particular radiofrequency electrical ablation, has been used in the treatment of tumors and other masses present in solid tissues such as the liver. Use of such techniques in the lungs, however, entails some attendant complications and difficulties. First, the use of conventional electrical ablation probes requires piercing into the thoracic cavity and into the lung, with a consequent high likelihood of pneumothorax, excessive bleeding and other complications. Moreover, these transthoracic ablation probes are rigid and may not be able to reach certain areas of the pulmonary anatomy.
While there have been some attempts to pursue radiofrequency electrical ablation via bronchoscopes inserted into airways, these attempts are limited by the confines of the airway passage and the reach of the bronchoscope—which cannot enter into very small peripheral lung passages—and accordingly may not be able to position the probes ardor deliver sufficient energy to treat tissue such as lung nodules adequately. Damage to the airway itself may result from the treatment process. Additionally, it will be noted that visualization and localization of the tissue region to be treated may present challenges, especially for tissue regions deep in the lung.